Subminiature fuses are generally vacuum sealed, are air tight, or have no separate pressure relieving passageways, as shown by U.S. Pat. Nos. 4,899,123, 4,417,226, 4,349,805; 3,227,841 and 3,110,787. Also, the prior art generally requires a refractory fuse housing U.S. Pat. No. 3,227,841; a metal liner, U.S. Pat. No. 4,899,123 or an arc quenching filler U.S. Pat. No. 3,110,787.
The prior art subminiature fuses are generally prone to being damaged easily if there is a high pressure build up in the fuse caused by the fuse blowing.
If the cover of the fuse fractures, or releases from the fuse, it could cause damages to surrounding parts on the circuit board. Some of the prior art attempts to provide the fuse with a plurality of locking devices. U.S. Pat. No. 4,628,293 shows using three annular ribs on the base. The annular ribs are rounded.
Therefore, it is an object of the present invention to provide a subminiature fuse that will substantially alleviate some of the above problems encountered by the prior art.
An object of the present invention is to provide a subminiature fuse having a plurality of vent passageways extending from inside the fuse to the outside of the fuse.
Another object of the present invention is to provide a subminiature fuse having a plurality of locking projections on the fuse base wherein said locking projections have an upper frustro-conical surface and a lower locking rounded surface that cooperates with corresponding grooves in the fuse cover, and a plurality of pressure relieving passageways extending from the upper surface of said fuse base to the outside of said fuse.
Other objects will become apparent to those skilled in the art when the specification is read in conjunction with the attached drawings.